Physical Science

“On a cosmic scale, our life is insignificant, yet this brief period when we appear in the world is the time in which all meaningful questions arise.” -Paul Ricoeur What you see is what you get, except when it isn’t. We’re all familiar with Hubble’s law, or the notion that the Universe is expanding, and…

Supertides are real!

“But less intelligible still was the flood that was caused by forty days’ rain, and forty nights’. For here on the moors there were some years when it rained for two hundred days and two hundred nights, almost without fairing; but there was never any Flood.” -Halldór Laxness Once every 18 years, a French Abbey…

I mentioned last week that I’m giving a talk at Vanderbilt tomorrow, but as they went to the trouble of writing a press release, the least I can do is share it: It’s clear that this year’s Forman lecturer at Vanderbilt University, Chad Orzel, will talk about physics to almost anyone. After all, two of…

“There is, I believe, in every disposition a tendency to some particular evil, a natural defect, which not even the best education can overcome.” “And your defect is a propensity to hate everybody.” “And yours… is wilfully to misunderstand them.” -Jane Austen Every time we go to higher and higher energies in our particle accelerators,…

How Does Angular Momentum Emerge?

Yesterday’s post about VPython simulation of the famous bicycle wheel demo showed that you can get the precession and nutation from a simulation that only includes forces. But this is still kind of mysterious, from the standpoint of basic physics intuition. Specifically, it’s sort of hard to see how any of this produces a force…

John Urschel Does Math

My main line of research is in algebraic graph theory. In particular I am interested in the eigenvalue spectra of Laplacians on graphs. Those don’t often get mentioned over at HuffPo, so I raised an eyebrow when I saw this: A mathematician by the name of John Urschel recently published a complex paper in the…

New Problem Of the Week

As you might have noticed, Sunday Chess Problem had the week off. If you really need to get your fix, though, you can have a look at this web page I made for my chess problems. You’ll recognize a few of them from the Sunday Chess Problem series. I did, however, manage to get the…

A paper just out now in PNAS by Noah Diffenbaugh, Daniel Swain, and Danielle Touma shows that “Anthropogenic warming has increased drought risk in California.” From the abstract: … We find that although there has not been a substantial change in the probability of either negative or moderately negative precipitation anomalies in recent decades, the…

The Emergence of Angular Momentum

The third of the great physics principles introduced in our introductory mechanics courses is the conservation of angular momentum, or the Angular Momentum Principle in the language of the Matter and Interactions curriculum we use. This tends to be one of the hardest topics to introduce, in no small part because it’s the last thing…

“Studying whether there’s life on Mars or studying how the universe began, there’s something magical about pushing back the frontiers of knowledge. That’s something that is almost part of being human, and I’m certain that will continue.” -Sally Ride When Curiosity landed on the martian surface in 2012, surviving “seven minutes of terror,” it went…